kristen spent last year on the obama campaign trail and talks about the moment she knew the president was headed to victory. i began by talking to her about the challenges of living on the road for months. >> it was a challenge, but it was so thrilling. i'd always wanted to cover a campaign at the national level. so i woke up and i was excited every day. it was just a thrill to literally watch history unfold and to be a part of that. the biggest challenge was that it was exhausting, and there was a physical toll, which i wasn't prepared for. i wasn't prepared for getting sick on the campaign trail. it's not easy to just call up your doctor and say, hey, i'm not feeling well. you have to literally do a lot of improvisation and, remember, you're eating sort of what's put in front of you. when you're on the campaign trail, 90% of the food is a carbohydrate. so that's a big challenge. especially someone like myself, who likes to be healthful and exercise a lot. exercising goes out the window. you try to sneak in sit-ups before you go to bed. but you're not getting a lot of sleep. so that